The use of creels for supporting a plurality of yarn packages is well known in the textile industry and has application in other stranded materials based industries. However, despite their widespread use, the task of loading a creel remains an extremely labor intensive operation involving both gross and fine motor skills. The nature of the loading tasks presents various risks to repetitive motion injuries such as carpal tunnel syndrome, spinal injuries, and other musculo-skeletal maladies. This is particularly the case in the manufacture of woven carpets, where the strength, durability, and weight of the yarns to manufacture such carpets typically requires yarn spools, known as packages, that have considerable weight in order to provide sufficient strand lengths to effectively feed modern high-speed processing systems.
Modern high-speed processing systems require a continuous, uninterrupted supply of yarns, fed from a plurality of yarn packages supported throughout the creel. The yarn package supports are arrayed on a plurality of support posts extending from the free standing frame of the creel, which is positioned to feed the manufacturing process. Eyelets or other guide means are provided throughout the creel through which each of a plurality of yarn strands are fed to the processing system. Usually a pair of package supports are configured in alignment with a single eyelet and the respective yarn strands from the paired packages are tied or otherwise attached in series to alternately feed the process. Due to the varying weights and strengths of a particular yarn package selected for a particular package support on the creel, as well as variations in the strand lengths of like yarn packages, the yarn will be depleted from the packages at irregular intervals. Consequently, laborers tasked to load and maintain the supply of yarns must constantly monitor the yarn packages and replace them at frequent intervals as the yarns are dispensed to feed the manufacturing process.
Replacement of a yarn package in a creel typically requires a worker to rotate a depleted package support out of the creel from its feed position to a loading position; remove and dispose of a spent cone from the package holder; lift the replacement yarn package from a delivery platform, such as a pallet; transport the package to the indicated package support; manipulate the package to mount it on the package support; rotate the replenished package support into the creel; and tie or otherwise secure the lead end of the replenished yarn package to the tail end of the paired feeding yarn package. A typical package will weigh on the order of 8 to 14 pounds.
In a given shift, a textile worker tasked to load and maintain the creel in a conventional process will lift, transport, and manipulate as much as six thousand pounds of yarn packages. Because the package supports are arrayed at varying heights and distances from the delivery platform, the typical laborer is subjected to significant risk of musculo-skeletal injuries presented at each step of the yarn package replacement process.
For example, in creels equipped with yarn package supports such as that disclosed in U.S. Pat. No. 4,880,184, rotation of the package support requires a two handed operation. First, the laborer must pull the locking handle with one hand in order to unlock the package support before it may be rotated from its use position. The laborer must then grasp the cone holder with the other hand to rotate the spent package cone to the loading position.
During lifting, transport and manipulation of a new cone, laborers will have a tendency to grasp the yarn package at the end of the package and either extend the fingers into the cylindrical cone and secure the outer diameter of the package with the thumb or vice versa, focusing the stresses in the hands, wrists, and forearms. In addition, the subsequent lifting, transport and manipulation of yarn package when grasped in this manner is particularly stressful on the musculo-skeletal tissues of the hand, wrist, and arm. Due to the dispersion of the package supports within the creel, frequent bending, lifting, and reaching is required to load the package, leading to shoulder, back and other musculo-skeletal stresses.